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Application of the HEC-HMS hydrological model in the Beht watershed (Morocco)
Fatima Daide1*, Rachida Afgane1, Abderrahim Lahrach1, Abdel-Ali Chaouni2, Mohamed Msaddek1, Ismail Elhasnaoui3
1Functional Ecology & Environmental Engineering laboratory, Sidi Mohamed Ben Abdellah University, Morocco 2 Intelligent Systems, Georesources & Renewable Energies laboratory Sidi Mohamed Ben Abdellah University, Morocco 3 Mohammed V University, Mohammadia School of Engineers, Rabat, Morocco
Abstract. This work focused on the collection and preparation of the data required for the hydrological modelling of the Beht catchment area, which covers an area of 4560 km2 with a perimeter of 414 km, by
combining the various spatial technologies, in particular geographical information systems (GIS), remote sensing, and digital terrain models (DTM), with hydrological models in order to prepare for spatial hydrological modelling used for flood forecasting. The methodology consists, at first, in the automatic extraction of the sub-basins and the drainage network. Then, edit these data using the HEC-GEO-HMS extension, and the preparation of the land use and land cover data for the elaboration of a Curve Number (CN) map of Beht watershed, then the import of the basin model into the Hydrologic Modeling System (HEC-HMS) to simulate the surface runoff using six extreme daily time series events.
Keywords: Spatial hydrological modelling; Remote sensing; Geographic Information Systems (GIS); Digital Terrain Models (DTM); Curve Number (CN); HEC-GEO HMS; HEC-HMS.
*Corresponding author:[email protected]
© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0
(http://creativecommons.org/licenses/by/4.0/).
E3S Web of Conferences 314, 05003 (2021) https://doi.org/10.1051/e3sconf/202131405003 WMAD21
1 Introduction
Over the last years, Morocco has experienced a number
of tragic flood events that have generated flooding in
several regions of the country due, on the one hand, to
population growth and urban, agricultural, industrial and tourism development which lead to an increasing
occupation of vulnerable areas and, on the other hand,
to the aggravation of extreme conditions (drought and
floods) as a result of climate change [1]. To deal with
this flood risk, a set of tools has been developed to
understand the hydrological functioning of basins. In
this context, hydrological modeling is the most
adequate tool to understand the water cycle on small and large scales.
The Soil Conservation Service (SCS) curve number
(CN) method is one of the most popular methods for
computing the runoff volume from a rainstorm [2]. It is popular because it is simple, easy to understand and
apply, and stable, and accounts for most of the runoff
producing watershed characteristics, such as soil type,
land use, hydrologic condition, and antecedent
moisture condition [3, 4]. The SCS-CN method was
originally developed for its use on small agricultural
watersheds and has since been extended and applied to
rural, forest and urban watersheds [5]. Due to its low
input data requirements and its implementation within
GIS, it has been incorporated in many widely used
hydrological models. In recent years, the method has received much attention in the hydrologic literature.
The SCS-CN method was first published in 1956 in
Section-4 of the National Engineering Handbook of
Soil Conservation Service (now called the Natural
Resources Conservation Service), U. S. Department of
Agriculture. The publication has since been revised
several times. Despite several limitations of the method
and even questionable credibility at times, it has been
in continuous use for the simple reason that it works fairly well at the field level. [6, 7, 8, 9, 10, 11]
The Hydrologic Modeling System HEC-HMS,
which is a hydrologic modeling software developed by the US Army Corps of Engineers Hydrologic
Engineering Center (HEC) is an integrated modeling
tool for all hydrologic processes of dendritic watershed
systems. It consists of different component processes
for rainfall loss, direct runoff, and routing. HEC-HMS
has become very popular and been adopted in many
hydrological studies because of its ability in the
simulation of runoff both in short and longtime events,
its simplicity to operate, and use of common methods
[12]. Hydrographs developed by HEC-HMS either
directly or in conjunction with other software’s are used for studies of urban drainage, water availability,
future urbanization impact, flow forecasting, flood
damage reduction, floodplain regulation, and systems operation [13].
The objective of this study is to apply GIS software
and remote sensing to determine Curve Number for
Beht watershed to study a rainfall-runoff model based
on the HEC-HMS, to calculate runoff volume and peak discharge.
2 Materials and methods
2.1 Study area
The Beht catchment area is located in northwestern
Morocco and covers an area of approximately 4560
km2 in the southwestern part of the Sebou basin. It is
bounded to the north by the Gharb plains and the
Meknes shelf, to the south by the Oum-Erbia basin, to
the west by the Bouregregreg basin and to the east by
the Middle Atlas. Its boundaries are located between
the meridians 5° and 6° West and the parallels 33° and 34° North.
This basin is located between the Lambert coordinates
(X1 = 430347.24; Y1 = 281864.43) and (X2 = 529704.23; Y2 = 386110.82).
Fig. 1. Geographical location of the catchment area of Beht
The Beht watershed has an elongated shape
following a SW-NE direction. The Gravelius index of
compactness, calculated for this basin, is about 1.86. It
is therefore eight times longer than it is large, which allows a rapid collection of water towards the outlet. It
can also be assimilated to a rectangle of the same
surface area, which is 202.5 km long and 22.5 km in
width. The Beht catchment area has a Mediterranean
climate (semi-arid to humid). It presents a double
gradient of decreasing intensity from South to North
and from East to West. This climate is marked by
frequent summer droughts and violent stormy rainfall.
Rainfall is marked by annual fluctuations. They vary
from 550 mm in the North-West of the basin to about
900 mm in the South-East. Temperatures show a clear
variation in space and time. High altitudes are characterized by low temperatures, ranging from -
0.9°C in winter to 25°C in summer. While low altitude
regions record temperatures of around 15°C in the winter and 34°C in the summer.
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E3S Web of Conferences 314, 05003 (2021) https://doi.org/10.1051/e3sconf/202131405003 WMAD21
The hydrological regime is characterized on the one
hand by floods recorded mainly during wet periods and
which ensures 80% of the annual liquid flow. On the
other hand, low water levels during the dry season, when liquid flows are very weak at around 20%.
2.2 Data processing
The work methodology focuses on the preparation of
the data necessary for the spatial hydrological modeling of the basin, from Arc Hydro and HEC-
GeoHMS; extensions of a geographic information
system (GIS), as well as the elaboration of land use and
soil maps and the calculation of the Curve Number
grid, then the import of the basin model into HEC-HMS.
2.2.1 Delimitation of the watershed
The traditional method used to delineate a watershed
area from the topographic map takes time and is
inaccurate and it has been replaced by the automatic extraction from a digital Terrain Model [14].
So, the first step consists in the automatic
delimitation of the Beht watershed based on the digital
terrain model, derived from the ASTER sensor, which
is characterized by its 30 m spatial resolution. Then,
the delimitation of sub-basins and the extraction of the
drainage network from the basin DTM [15]. Nine
operations are carried out to get the schematization of the basin model [16].
2.2.2 Land use map
It is determined through a supervised classification on
satellite images "ASTER" using an image processing
tool (ENVI: Environment for Visualizing Images).
There are six main types of land use in the Beht
watershed: Pastures covering almost 1/3 of the area,
which is equivalent to an area of 1471 km2. They are
geographically dispersed throughout the basin. This
natural vegetation develops according to the type of
soil conditions and climate. Followed by bare land,
which representing 23% of the total surface area, i.e.
1052 km2. They are mainly located upstream. Forests represent 20.6% of the surface area. They are grouped
in two lots located respectively on the middle and the
southern extremity of the basin. The agricultural lands
represent 18% of the land; they are mainly located up-
stream of the basin. Matorrals appear in the extreme
northwest of the study area representing 5.6% of the surface area. (Fig.2)
Fig. 2. Land use map
Because of the specific requirements of the chosen
modular combination, specifically the NRCS CN
(Natural Resources Conservation Service Curve
Number) method as a production function, the
elaboration of a land use map over the entire study area was a necessary step.
The information contained in this map should be
authentic to the classification of the NRCS (Natural Resources Conservation Service)[17], so we had to
make connections between the NRCS classes and the
map prepared by the satellite image classification
method. Then, we reclassified the thematic classes defined above as shown in the table below:
Table 1. Land Use Class Reclassification
2.2.3 Soil map
The nature of the soil affects the rate of flood rise and
volume, as well as, the infiltration rate, moisture
content, storage capacity, initial losses, runoff
coefficient (Cr) are all related to the soil type.
The soil map was recovered from the National Institute
of Agronomic Research (INRA) (published in 2001)
(Fig.3), and digitized in order to get a standard soil
map. The main classes of soils outcropping in the Beht catchment area: Calcimagnesic soils (CAL.S),
First classification Reclassification
Class
Number
Class Name Class
Number
Class Name
1 Water 1 Water
2 Forest 2 Forested area
3 Reforestation
4 Bare Soil 3 Non-forested
area 5 Built
6 Low vegetation 4 Low vegetation
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Isohumic soils (ISO.S), Crude mineral soils (CM.S),
Poorly developed soils (PD.S), Vertisols and
assimilated soils (VA.S), Fersiallitic soils (FER.S),
Hydromorphic soils (HYD.S), Brown soils (BR.S).
Fig. 3. Soil map of the study area (INRA, 2001: digitized)
The soil cover for the entire watershed shows a significant dominance of poorly developed soils, which
can form associations with crude mineral and
calcimagnesic soils (33.1%). The poorly developed
soils and the association "poorly developed soils and
raw mineral soils" are located in the upstream part of
the watershed; they are mainly associated with alluvial
deposits. The association "poorly developed soils and
calcimagnesic soils" is present mainly on the right bank downstream of the basin.
Approximately 30% of the watershed is covered by
brown soils and associations of brown soils and hydro-
morphic or poorly developed soils. These soils are
mainly present in the middle of the watershed,
although they can also be found further south in the
upstream part of the watershed.
In the northeast and southwestern extremities, vertisols and assimilated soils are present, with a
percentage around 11%. Isohumic soils and the soil
association isohumic and calcimagnesic soils
downstream of the watershed, have a proportion of
11.2%.
The basin has other types of soil and soil
association, such as: hydromorphic soils, fersiallitic
soils, the association of raw mineral soils, poorly evolved soils and hydromorphic soils, the association
of fersiallitic and poorly evolved soils, the association
of brown soils and raw mineral soils etc..., but in small
or even very small proportion.
The soil classification used by the Soil
Conservation Service method is the hydrological
classification. It is a classification that consists of
grouping soils into four hydrological groups (A, B, C,
D), [18], based on their estimated infiltration potential.
As a result, soils are assigned to one of four groups
based on their infiltration rate; A; soil having high
infiltration rates, B; soils having moderate infiltration
rates, C; soils having slow infiltration rates, and D;
soils having very slow infiltration rates [17].
The transition from soil classification to hydrological classification is made by providing
information on soil texture according to the
composition of sand(S), silt (St), clay(C) and organic
matter (O), because Soil texture information is
essential to determine the runoff coefficient [19]. The
values of these components are given in the following
table:
Table 2. Soils textural classes and its associations according to their correspondence in hydrological class
Soil name Area(%) Hydrological grp Texture
PD&CM 15.6 C StSC
BR 15 A StSC
PD 13.1 B StSC
BR&HYD 12.7 D C
VSA 10.8 D CStO
CAL&ISO 8 C StSC
CM 4.6 A StSC
CALPD 4.4 A StSC
ISO 3.2 C StSC
CAL 2.8 B StSC
BR&PD 2.7 C StSC
HYD 2 C StSC
FER 1.3 B StCS
CM&PD&HYD 1 B StSC
FER&PD 1 A StSC
BR&CM 0.6 B StSC
BR&CAL 0.4 D StSC
BR&ISO 0.3 C StSC
VSA&HYD 0.2 B C
VSA&PD 0.1 B C
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Fig. 4. Pedology of the Beht Watershed according to hydrological classification
From this map it can be concluded that the most
dominant class is class C, which shows that the soils
have slow infiltration rates, therefore a relatively high
runoff.
3 Generation of the curve number map
3.1 Calculation of the CN grid
The SCS has developed a soil characterization system
based on the hydrology and land use group called the
Curve Number (CN). Values range from 0 to 100; A
CN value of 0 indicates no runoff potential, while a
value of 100 indicates that all precipitation runs off
[18]. In other words, a value of 100 is assigned directly to the water surface and 0 for highly permeable soils
with a high infiltration potential.
3.1.1 Preparation of the CN-Lookup table
The look-up table will contain the Curve Number for
different combinations of land use and soil groups. The
purpose of this table is to define the CN values for each
land use/hydrology group combination. In this case we
will use the SCS curve numbers that are available from
the literature (SCS reports, or SCS tables). The table
below summarizes the CN-Lookup table created from
the land use classes and their correspondence in
hydrological groups while following the TR-55
standard and the NRCS land use table:
Table 3. Attribute table of correspondence between land use
and soil type
Class
Number
Class Name A B C D
1 Water 100 100 100 100
2 Wooded land 45 66 77 83
3 Unforested land 77 86 91 94
4 Low vegetation 60 71 78 81
3.1.2 Creating the CN grid
HEC-GeoHMS is used to create the CN grid. It
combines the union result between type and land use,
the CN-Lookup table and the DTM of the basin. But
before proceeding, it is necessary to add a new field named "LandUse" in the union table. This field will
contain the land use category information, and will link
the union table to the CN-Lookup table.
Fig. 5. CN map of Beht watershed
The final map of curve number of Beht watershed
(Fig.5) shows an average CN of 78 which means that
the basin have a moderate high runoff, and this is due
to the clay type soil dominated by poorly developed soils, brown soils and vertisols assimilated soils and
also, the vegetation cover that is marked by significant
presence of pasture lands. These results are nearly
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E3S Web of Conferences 314, 05003 (2021) https://doi.org/10.1051/e3sconf/202131405003 WMAD21
similar to the study realized by [20] who found that the
average curve number in the Sebou basin is 82.
The choice of the Curve Number depends, in addition
to the soil type and land use, on the antecedent soil
moisture conditions (AMC). These can be dry (I),
moderate (II) or wet (III) [21]. The values provided in
the Attribute Table (tab.3) are representative of average initial moisture conditions (CNII) (Fig.5) and the
Curve Number CNI and CNIII are calculated directly
using the [22] equations below:
𝐶𝑁(𝐼) =4.2×𝐶𝑁(𝐼𝐼)
10+0.058×𝐶𝑁(𝐼𝐼) (1)
𝐶𝑁(𝐼) =4.2×𝐶𝑁(𝐼𝐼)
10+0.058×𝐶𝑁(𝐼𝐼) (2)
Soil moisture status is determined based on
precipitation in the watershed during the last five days
before the event in question, and by season (low and rainy seasons).
The curve number in the conditions I and III are 51
and 89 respectively.
4 HMS model
The HEC-HMS model is physically based and
conceptually semi-distributed model designed to
simulate rainfall-runoff processes in a wide range of geographic areas, from large river basin to small urban
and natural watershed runoffs. It makes it easy to
perform huge tasks related to hydrological studies,
including losses, runoff transform, open channel
routing, weather data analysis, rainfall-runoff
simulation and parameter estimation [23, 24].
Moreover, the HEC-HMS uses separate models that
compute runoff volume, models of direct runoff, and models of baseflow. It has nine different loss methods;
some of it is designed for event simulations, whereas
others are for continuous simulation. It also has seven
different transformation methods, Clark Unit
Hydrograph Banitt [25] methods that have been
applied successfully to simulate long-term stream
flows.
In this study, the Soil Conservation Service Curve Number loss method was selected to estimate direct
runoff from a specific or design rainfall [26]. This
method normally calculate the runoff volume by
computing the volume of water that is intercepted
infiltrated, stored, evaporated, or transpired and
subtracting it from the precipitation. It was chosen
because it is a simple method for the estimation of the
direct runoff from a storm rainfall event, and it relies only on the curve number, which is a function of the
soil type and land use/cover that are the major runoff-
producing watershed characteristics and also it is
commonly used in different environments and provides
better results compared to initial and constant loss rate
method [27]. The SCS-CN method is based on the fact
that the accumulated rainfall-excess depends on the
cumulative precipitation, soil type, land use and the
previous moisture conditions as estimated in the
following relationship [21]:
𝑃𝑒 =(P−Ia)2
P−Ia+S (3)
Where Pe is the accumulated precipitation excess at time t (mm); P is the accumulated rainfall depth at time
t (mm); Ia is the initial abstraction (mm) = 0.2S; and S
is the potential maximum retention (mm).
The maximum retention, S, and watershed
characteristics are related through an intermediate
dimensionless parameter, the curve number (CN) as:
𝑆 = 25400 −254×𝐶𝑁
𝐶𝑁 (4)
Where CN is the SCS curve number used to represent the combined effects of the primary characteristics of
the catchment area.
Regarding the transform method, the Soil
Conservation Service Unit Hydrograph model was
chosen to transform excess precipitation into runoff.
The lag time (Tlag) is the only input for this method. It
is the time from the center of mass of excess rainfall to
the hydrograph peak and is calculated based on the time of concentration Tc, as:
𝑇𝑙𝑎𝑔 = 0.6𝑇𝑐 (5)
Where Tlag and Tc are in minute.
The routing method selected is the Muskingum
method, which was developed by McCarthy [28]. It
allows calculating the outflow hydrograph at the
downstream end of the channel reach from the inflow
hydrograph at the upstream end. Two parameters are needed; travel time (K) of the flood wave through
routing reach; and dimensionless weight (X) which
corresponds to the attenuation of the flood wave as it
moves through the reach. The routing parameters in the
models are usually derived through calibration using
measured discharge hydrographs [29].
4.1 Model Calibration and Validation
In order to identify the key parameters and parameter
precision required for calibration, a sensitivity analysis
is usually used in most modelling studies [30, 31]. The sensitivity parameters were selected based on their
effect on peak discharge and total volume. The model
calibration was done with the Univariate Gradient
optimization package and Peak-Weighted Root Mean
Square Error (PWRMS) objective function because of
their simplicity and performance [26]. In this study, six
flood events (four for calibration and two for
validation) in the period from 1996–2014 were selected for calibration and validation. Watershed parameters
such as curve number, initial abstraction, Tlag and
baseflow possibly will need modification to produce
the best fit between simulations and observations. For
validation, the simulated data must be computed and
compared with the observed data.
Statistical assessment criteria as relative bias error
functions proposed by Najim [32], Nash–Sutcliffe Efficiency (NSE) by Nash and Sutcliffe [33], Ratio of
standard deviation of observations to root mean square
error (RSR) by Moriasi et al. [34] and coefficient of
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E3S Web of Conferences 314, 05003 (2021) https://doi.org/10.1051/e3sconf/202131405003 WMAD21
determination (R2) as described in Neter et al. [35]
were applied to evaluate the performance of the model
and the selected loss and transform methods.
5 Results and discussion
5.1 Calibration
The results of the hydrological model in this study
showed a reasonable fit between the simulated and
observed hydrographs after optimization; the shape of
the hydrograph and the time of peak had a good match
(fig.6). In the majority of events, the hydrograph shape
was accurately reproduced in the model output.
However, the volume of runoff was overestimated in
events 1, 2 and 3 and underestimated for the event 4. The modelling results of peak discharge, total volume,
and their relative errors with respect to the observed
data, the Nash Sutcliffe Efficiency, the coefficient of
determination and ratio of standard deviation of the
observation to the root mean square error (RSR) values
during calibration are mentioned in Table below.
Figure 7 (Event 1) show correlation values between the
observed and simulated flows (sample event).
Fig. 6. Simulated and observed hydrograph during
calibration for event 1.
Fig. 7. Correlation between observed and simulated
flow during calibration for event 1.
Table 4. Simulated and observed peak discharges and total volume and their evaluation criteria during calibration.
The calculated values of the percent error in total
volume and peak flow between simulated and observed
values in all simulations before optimization was approximately high, with mean values of 6.14% for the
peak flow and 14.15% for the total volume. According
to this result, a sensitivity analysis was conducted to
determine the most sensitive parameter. It was found
that the initial abstraction and curve number were more
sensitive, travel time K less sensitive and lag time was
insensitive.
After optimization, the values in this study were reduced to 0.1 to 6.1% for the peak flow and 0.86 to
17% for the total volume, with mean values of 2.5%
and 4.8%, respectively (Table 4). The result is very
good according to Najim et al. [32] and Cheng et al.
[36] who recommended that the acceptable ranges of
relative percent errors between the observed and
simulated values should be below ±20%. The results
showed also a relatively close agreement between the observed and simulated peak flow values at the period
of calibration (R2 = 0.842) (Fig.7). Based on the
classification mentioned in Zou et al. [37] the mean
correlation coefficient obtained in this study can be
considered as strong (>0.8). Regarding the Nash–
Sutcliffe Efficiency (NSE) criteria, better results were
obtained between the simulated and observed values,
with a mean NSE value of 81.5% (Table 4), which means that the model performs very well. The model
simulation can be judged as satisfactory if Nash–
Sutcliffe Efficiency is greater than 50%, good if it is
greater than 65%, and very good if it is greater than
75% [34]. The mean value of Ratio of standard
deviation of observations to root mean square error
(RSR) obtained was 0.1, so according to Moriasi et al.,
[34], the model can be said as satisfactory if RSR<=0.7. The four statistical evaluation criteria with
mean values of REP = 2.5%, REV = 4.8%, NSE = 0.815,
R2 =0.842, RSR=0.1 showed good simulation between
the estimated and observed values.
5.2 Validation
The table below shows the validation of the simulated
results (Table 5) of peak discharge, total volume, and
their relative errors, the Nash–Sutcliffe Efficiency
(NSE), the coefficient of correlation (R2) and the
(RSR) values. Figure 8 and 9 showed the simulated and observed hydrographs and their correlation
respectively (Sample validation events are presented).
0
50
100
150
200
250
300
350
400
Outflow Obs flow
R² = 0.9189
0
50
100
150
200
250
300
350
400
0 50 100 150 200 250 300 350 400
Ou
tlfl
owm
3/s)
Obs flow (m3/s)
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Fig. 8. Simulated and observed hydrograph during
validation for event 5.
Fig. 9. Correlation between observed and simulated
flow during validation for event 5.
Table 5. Simulated and observed peak discharges and total
volume and their evaluation criteria during validation.
The result obtained shows that the simulated values are
a little close to the observed ones for all the events
(Table 5) with an overestimation for the simulated values in peak flow. The mean relative percent error
between the observed and simulated values of total
volume and peak flow is 9.6% and 1.69%, respectively.
In relation to the coefficient of determination there is a
quite close match between the observed and simulated
peak flow values during validation (R2 = 0.807).
Considering the Nash–Sutcliffe Efficiency (NSE)
criteria, the results obtained between the simulated and observed values is 63.4% and the RSR criteria is 36%
According to Moriasi et al. [34], the model simulation
can be judged as satisfactory. Usually, the statistical
evaluation criteria with mean values of REP = 9.6%,
REV = 1.69%, NSE = 0.63, and R2 =0.870, RSR=0.36
show good simulation between the estimated and
observed values.
The SCS loss and transform methods showed good results on the simulation of the validation events and
the results of the statistical evaluation criteria showed a
satisfactory performance of the HEC-HMS model in
predicting the peak flow and total volume in the Beht
watershed. To increase the performance of the model
in simulating the runoff, It is recommended to set up
more rain gauge stations in the basin because the use of
3 stations is not sufficient to reduce the effect of spatio-
temporal heterogeneity in precipitation, also for the
flow data which are not enough to estimate perfectly the flows at the outlet, it is necessary to set up more
hydrometric stations in the upper areas of the
catchment, and to identify regional valid unit
hydrographs and curve number as Zelelew[38] and
Hawkins [39] recommend.
6 Conclusions
Our project is a perspective study which is inserted on
the preparation of the data necessary as a first step for
the hydrologic simulation using HEC-HMS model.
The delimitation of sub-basins, the extraction of the
hydrographic network and the development of the soil
and land use databases was a very important step in
this study. These were used with ArcGIS and HEC-
GeoHMS to estimate the curve number in three states (CNI (dry), CNII (medium) and CNIII (wet)), and to
determine a curve number map that has been used
successfully for estimating surface runoff from the
Beht watershed. The results demonstrate that the
watershed is characterized by clay soil type dominated
by poorly developed soils, brown soils and vertisols
assimilated soils and a vegetation cover that is marked
by significant presence of pasture lands which occupy more than 32%, followed by forests, agricultural land
and bare land. The CN of the Beht watershed is
medium to high, with an average value of 78, which
means that the basin have a moderate runoff potential,
the most runoff-producing areas have a high runoff
coefficient.
The model calibration was used to optimize the
parameters and the most sensitive parameter in the simulation was the initial abstraction followed by the
curve number. After optimization the peak flow and
total volume of all events are very close to the
observations. The performance of the HEC-HMS
model was very good in terms of relative error
functions, Nash-Sutcliffe Efficiency, coefficient of
determination and Ratio of standard deviation of
observations to root mean square error RSR based on the selected loss, transform and flow routing methods.
Finally, the results obtained showed that the model
can be judged as valid and good in terms of evaluation
criteria, but we suggest to set-up other meteorological
and hydrometric stations in order to generate more
details and to increase the performance of the model in
the simulations.
References
1. PDAIRE (Plan directeur d'aménagement
intégré des ressources en eau). Agence Du
Bassin Hydraulique Du Sebou (2011).
0
50
100
150
200
250
outflow obs flow
R² = 0,870
0
50
100
150
200
250
300
0 50 100 150 200 250
Sim
ula
ted
flo
w (
m3/s
)
Observed flow (m3/s)
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